Bone compression device and method

ABSTRACT

In one form, a bone compression device is provided having a shape-retentive bone plate with an initial, unflexed configuration and a flexed configuration. The bone plate may be shifted to the flexed configuration and secured to bones using bone screws of the bone compression device. Once the bone plate has been secured to the bones, the bone plate returns toward its unflexed configuration which compresses the bones.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/058,695, filed Mar. 2, 2016, which claims the benefit of U.S.Provisional Patent Application No. 62/127,609, filed Mar. 3, 2015, whichare all hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The invention relates to the stabilization of bones and, moreparticularly, to devices for compressing bones together to encouragebone growth.

BACKGROUND

Nitinol staples are often used to stabilize bones in orthopedicpodiatry, hand, and wrist surgeries. As used herein, the term “bone” isintended to refer to whole bones, bone fragments, and other portions ofthe skeleton. Nitinol staples may be used to compress a pair of bonesseparated by a cut or break to encourage healing. Nitinol staples mayalso be used to compress a pair of bones on opposite sides of an implantto encourage fusion of the bones and implant construct.

A nitinol staple may be implanted by first drilling holes for legs ofthe staple in the bones sought to be stabilized. The legs of the stapleare splayed apart, which elastically deforms the staple, and areinserted into the holes. The resilient properties of the nitinol stapletend to draw the legs back together which compresses the bones. Thecompressive force applied by the staple encourages bone growth betweenthe bones.

A nitinol staple provides a limited amount of compression which is inacceptable in some applications. In other applications, however, agreater amount of compression or increased stability is desired suchthat two staples are implanted in the bones. Specifically, one staple isimplanted in one side of the bones and the other staple is implanted inan opposite side of the bones. Implanting two staples on opposite sidesof the bones may complicate the surgical procedure. Further, in someapplications, a greater amount of compression and/or increased stabilityis desired but the surrounding anatomy may inhibit the use of twostaples on opposite sides of the bones.

Another problem with the use of nitinol staples is that a large numberof staples are provided in a surgical kit. For example, a surgical kitmay include staples having different staple bridge lengths to positionthe legs of the staples different distances apart. For each staplebridge length, the surgical kit would also include staples withdifferent leg lengths. Providing both a range of staple bridge lengthsand staple leg lengths significantly increases the number of staplesrequired in the kit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a bone compression device having a boneplate and bone screws for securing the bone plate to bones;

FIG. 2 is a side elevational view of the bone plate of FIG. 1 showingthe bone plate in an initial, unflexed configuration with anintermediate portion of the bone plate having a curved shape;

FIG. 3 is a bottom perspective view of the bone plate of FIG. 1 showinglobes of the bone plate at opposite ends of the intermediate portion andan outer lip of one of the lobes;

FIG. 4 is a perspective view of one of a pair of manipulators forimplanting the bone plate of FIG. 1;

FIG. 5 is an enlarged perspective view of a distal end portion of themanipulator of FIG. 4 showing an opening sized to receive one of thelobes of the bone plate of FIG. 1;

FIG. 6 is a bottom plan view of the distal end portion of themanipulator of FIG. 4 showing a central cannula of the manipulator;

FIG. 7 is a schematic view showing the manipulators positioned above thelobes of the bone plate of FIG. 1 for connection therewith;

FIG. 8 is a cross-sectional view of the bone plate and manipulators ofFIG. 7 showing one of the manipulators connected to the associated boneplate lobe;

FIG. 9 is a bottom plan view of the manipulator of FIG. 8 connected tothe bone plate lobe showing a mating fit of the bone plate lobe and themanipulator;

FIG. 10 is a bottom perspective view showing both of the manipulators ofFIG. 7 connected to the lobes of the bone plate;

FIG. 11 is a side elevational view of the manipulators and bone plate ofFIG. 10 showing center lines of the manipulator cannulas oriented at anangle relative to one each other;

FIG. 12 is a view similar to FIG. 11 showing the manipulators pivotedtoward one another to an insertion orientation which bends theintermediate portion of the bone plate and reconfigures the bone plateinto a flexed configuration;

FIG. 13 is a bottom perspective view of the manipulators and bone plateof FIG. 12 showing centerlines of the manipulators aligned with throughbores of the bone plate lobes;

FIG. 14 is a perspective view of the manipulators and bone plate of FIG.12 showing a restraint being advanced onto the manipulators to securethe manipulators in the insertion orientation;

FIG. 15 is a side view similar to FIG. 14 showing the restraintresisting pivoting of the manipulators away from the insertionorientation thereof;

FIG. 16 is a top plan view of the restraint, manipulators, and boneplate of FIG. 15 showing cannulas of the manipulators aligned with thethrough bores of the bone plate lobes;

FIG. 17 is a side elevational view of the restraint and manipulators ofFIG. 15 being used to position the bone plate in the flexedconfiguration against bones;

FIG. 18 is an enlarged perspective view showing the manipulators of FIG.17 maintaining the bone plate in the flexed configuration against thebones;

FIG. 19 is a schematic view of a screw driver positioned to advance abone screw through a cannula of one of the manipulators;

FIG. 20 is a perspective view similar to FIG. 18 showing a shank portionof the bone screw being driven into the through bore of one of the boneplate lobes;

FIG. 21 is a view similar to FIG. 20 showing the screw driver driving ahead portion of the bone screw into the lobe through bore;

FIG. 22 is a schematic view showing the bone plate in the flexedconfiguration having been secured to the bone by the bone screws and themanipulators having been disconnected from the bone plate lobes;

FIG. 23 is a side elevational view of the bone plate of FIG. 22 securedto the bones in the flexed configuration with dashed lines showing thebone plate shifting toward the unflexed configuration thereof andcompressing the bones together;

FIG. 24 is a perspective view of a bone compression device including abone plate and manipulators that are releasably connectable to the boneplate;

FIG. 25 is a top plan view of the bone plate of FIG. 24 showing the boneplate in an unflexed configuration with an intermediate portion of thebone plate curved;

FIG. 26 is a top plan view similar to FIG. 25 showing the manipulatorssqueezed together which flexes the bone plate and straightens theintermediate portion of the bone plate;

FIGS. 27 and 28 are perspective views of the bone plate and manipulatorsof FIG. 26 showing a bone screw being driven into a through bore of thebone plate while the manipulators hold the bone plate in the flexedconfiguration;

FIG. 29 is a perspective view similar to FIGS. 27 and 28 showing themanipulators disconnected from the bone plate after the bone plate hasbeen implanted in the flexed configuration thereof;

FIG. 30 is a perspective view of a bone compression device including abone plate having integrated manipulators;

FIG. 31 is an enlarged, top plan view of the bone plate of FIG. 30showing a connection between a body of the bone plate and themanipulator;

FIG. 32 is a perspective view of another bone compression device havinga resilient body and bone screws;

FIG. 33 is a top plan view of the resilient body of FIG. 32 in anunflexed configuration;

FIG. 34 is a view similar to FIG. 33 showing end portions of theresilient body moved apart from one another to reconfigure the resilientbody to a flexed configuration;

FIG. 35 is a cross-sectional view taken across line 35-35 in FIG. 32showing a retention mechanism for keeping the end portion of theresilient body secured to the bone screw; and

FIG. 36 is a top plan view of a bone compression device similar to thebone compression device of FIG. 32 showing straight legs of theresilient body connecting a spring portion of the body to end portionsof the body.

DETAILED DESCRIPTION

In FIG. 1, a bone compression device 10 is provided having a bone plate12 with a body 14 for being secured to bones with bone anchors, such asbone screws 16. The bone plate 12 is made entirely or partially of ashape-retentive material that permits elastic deformation of the boneplate 12 and resiliently biases the bone screws 16 and bones connectedthereto together once the bone plate 12 has been implanted on the bones.In one form, the bone plate 12 is made of nitinol having superelasticproperties that permits the bone plate 12 to deform elastically as thebone plate 12 is flexed during implantation of the bone plate 12, asdiscussed in greater detail below. Once the bone plate 12 is implantedin a flexed configuration thereof, the bone plate 12 acts as a springand applies constant compression to the bones until the elasticallydeformed bone plate 12 returns toward its initial, unflexedconfiguration. This is an improvement over some prior compression boneplates that are plastically deformed to compress bones. In these boneplates, there may be spring back within the bone plate afterimplantation of the bone plate which reduces the compression applied tothe bones. As another example, the bone plate 12 may be made from ashape memory material, such as shape memory nitinol, which wouldcompress the bones by changing shape in situ from a flexed configurationto an unflexed configuration in response to the internal temperature ofthe patient.

The bone plate 12 has an initial, unflexed configuration where anintermediate portion 20 of the bone plate 12 is curved or bent, as shownin FIG. 2. With reference to FIGS. 7, 11, and 12, the bone plate 12 maybe flexed using an instrument 15 that includes a pair of manipulators17, 19. The manipulators 17, 19 are connected to the bone plate 12 andsqueezed together toward an installation orientation as shown in FIG.12, which bends the bone plate 12 to the flexed configuration whereinthe intermediate portion 20 is substantially straight. This loads theintermediate portion 20 and stores potential energy in the bone plate 12in a manner similar to compressing a spring.

A restraint 190 (see FIG. 14) may be connected to the manipulators 17,19 to hold the manipulators 17, 19 in the installation orientationwhich, in turn, maintains the bone plate 12 in the flexed configuration.Next, the assembled manipulators 17, 19 and restraint 190 aremanipulated to position the bone plate 12 in the flexed configurationthereof against bones 13, 15, as shown in FIG. 17. The bone screws 16are advanced through the manipulators 17, 19 and driven intothroughbores 22, 24 of the bone plate 12 to secure the bone plate 12 tothe bones 13, 15. With the bone plate 12 secured to the bones 13, 15 inthe flexed configuration, the bone plate 12 resiliently biases againstthe bone screws 12 as the bone plate 12 rebounds or returns toward itsunflexed configuration and the intermediate portion 20 returns indirection 30 toward its curved, unflexed shape 32, as shown by dashedlines in FIG. 23. Thus, the bone plate 12 urges the bone screws 16together as the bone plate 12 rebounds toward its unflexed configurationwhich compresses the bones 13, 15 together to heal a cut or break 280.The length of the bone plate 12 may be selected so that the bone plate12 does not completely return to its unflexed configuration after beingsecured to the bones 13, 15 so that the bone plate 12 continues tocontinuously apply compression to the bones 13, 15. Further, theintermediate portion 20 may flex as needed to accommodate subsidence ormovement of the bones 13, 15 post-surgery while continuing to compressthe bones 13, 15 together.

With reference to FIG. 1, the bone plate 12 has bone anchor receivingportions, such as lobes 40, 42, which include the through bores 22, 24.In one form, the bone compression device 10 includes retentionmechanisms 44 to resist back-out of head portions 46 of bone screws 16from the lobes 40, 42. In addition to resisting back-out of the bonescrew head portions 46, the screw retention mechanisms 44 may also fixthe bone screw head portions 46 to the bone plate lobes 40, 42. Byfixing the bone screw head portions 46 to the bone plate lobes 40, 42,the bone screws 16 and bone plate lobes 40, 42 form a rigid constructwith the bones 13, 15 while the intermediate portion 20 compresses thebones. This rigid construct permits a single bone plate 12 and twoscrews 16 to be used to stabilize bones where, in prior approaches, apair of nitinol staples would need to be used and would involve theinefficiencies associated therewith. In one form, the screw retentionmechanisms 44 includes cooperating threads on the bone screw headportion 46 and the lobes 40, 42. In another form, the screw retentionmechanisms 44 may include an expandable bone screw head portion 46 andan actuator for expanding the head portion 46 into engagement with thesurfaces of the through bores 22, 24, for example.

Another advantage of the bone compression device 10 is that a surgicalkit of several bone compression devices 10 may be provided with fewercomponents than a corresponding kit of nitinol staples. The kit of bonecompression devices 10 would include a plurality of bone plates 12having different lengths, a plurality of bone screws 16 having differentlengths, the manipulators 17, 19, and the restraint 190. The kit of bonecompression devices 10 could have fewer components than the nitinolstaple kit because the different length screws 16 in the kit could beused with any of the lengths of bone plate 12 in the kit. Thus, the kitof bone compression devices 10 would include one set of bone screws 16of different lengths, rather than a set of bone screws 16 of differentlengths for each bone plate 12. This is an improvement over acorresponding kit of nitinol staples which would include, for eachstaple bridge length, a set of staples with different leg lengths. Thesurgical kit may be provided with one length of manipulators 17, 19 thatcan be used with the bone plates 12 of different lengths or may providedwith a plurality of pairs of manipulators 17, 19 having differentlengths. Further, the surgical kit may be provided with one or more ofthe restraints 190. If one restraint 190 is provided, the restraint 190may be adjustable to fix the manipulators 17, 19 at different distancesapart.

With reference to FIG. 2, the bone plate 12 is shown in an initial,unflexed configuration with the intermediate portion 20 having anon-linear, curved shape. The curved shape of the intermediate portion20 orients center lines 50, 52 of the through bores 22, 24 to extend atan angle 53 relative to each other. The lobes 40, 42 each have aninstrument receiving portion 54 including a notched profile 56 with alip 58 and a depending flat 60. The lip 58 has a lower surface 62 thatis lifted upward by a lip engaging portion 66 (see FIG. 5) of theassociated manipulator 17, 19, as discussed in greater detail below.

With reference to FIGS. 3 and 5, the lobes 40, 42 of the bone plate areeach configured to form a mating, non-rotatable fit with a distal lobeengaging portion 72 of one of the manipulators 17, 19. Specifically, thelobe 42 has a rounded outer surface 80 that fits within a rounded innersurface 82 of the lobe engaging portion 72 of the manipulator 19. Thelobes 40, 42 are sized to fit within openings 74 of the manipulators 17,19 and the flats 60 of the lobes 40, 42 each abut a flat 76 of theassociated manipulator 17, 19. The abutting flats 60, 76 of the lobes40, 42 and manipulators 17, 19 resist turning of the lobes 40, 42 withinthe lobe engaging portions 72 as shown in FIG. 9.

With continued reference to FIGS. 3 and 5, the manipulator 19 has anotch 84 sized to receive a section of the intermediate portion 20 ofthe bone plate 12 as the manipulator 19 is advanced onto the lobe 42.The manipulator 19 has a fulcrum 88 for engaging the bone plate 12 asthe manipulator 19 is pivoted toward the manipulator 17 to bend the boneplate 12 as discussed in greater detail below. The fulcrum 88 includes asurface 90 that rests upon an upper surface 92 of the bone plate 12, asshown in FIG. 8. Further, the notch 84 includes walls 160, 162 arrangedto abut sides 164, 166 of the intermediate portion 20 and resistrotational movement between the lobe 24 and the manipulator 19.

Returning to FIG. 5, the manipulator 19 has an aperture 100 sized toreceive the lip 58 of the lobe 42. The aperture 100 has a width 102larger than a width 104 (see FIG. 3) of the lip 58. Turning to FIGS. 8and 18, the lip 58 of the lobe 42 extends over and is supported on anupper surface 150 of the lip engaging portion 66 with the lip 58positioned in the aperture 100 such that pivoting of the manipulator 19in direction 132 tightly engages the lip lower surface 62 and the uppersurface 150 (see FIG. 8).

With reference to FIG. 6, the manipulator 19 has a cannula 110 with acenter 112 and a wall 114 extending about the cannula 110. As notedabove, the lip engaging portion 66 of the manipulator 19 engages the liplower surface 62 of the lobe 42 and the surface 90 of the manipulator 19seats on the upper surface 92 of the bone plate 12 with the manipulator19 connected to the lobe 42. To provide leverage to bend the bone plate12, the manipulators 17, 19 have a distance 116 between the lip engagingportion 66 and the surface 90 of each manipulators 17, 19. In thismanner, pivoting the manipulators 17, 19 in directions 130, 132 as shownin FIGS. 11 and 12 tends to pull upwardly on the lip 58 and pushesdownwardly on the upper surface 92 of the bone plate 12 whichstraightens out the bone plate intermediate portion 20. Additionally,the manipulators 17, 19 have a length 136 that provides additionalleverage for bending the bone plate 12 as shown in FIG. 4.

With reference to FIGS. 7-23, a method of applying compression to thebones 13, 15 using the bone plate 12 is shown. Initially, the lobeengaging portions 72 of the manipulators 17, 19 are connected to thelobes 40, 42 of the bone plate 12. With reference to FIG. 7, themanipulator 19 is maneuvered in direction 140 to position the lipengaging portion 66 in the notched profile 56 of the lobe 42 below thelip 58. With the lip engaging portion 66 engaged with the underside ofthe lip 58, the manipulator 19 is then pivoted in direction 142 whichshifts the notch 84 downward onto the intermediate portion 20 of thebone plate 12 and seats the lobe engaging portion 72 on the lobe 42.

With reference to FIG. 8, the manipulator 19 is shown after pivoting indirection 142 such that the upper surface 150 of the lip engagingportion 66 is engaged with the lower surface 62 of the lip 58, the flat76 of the manipulator 19 is engaged with the flat 60 of the lobe 42, andthe surface 90 of the manipulator 19 is engaged with the upper surface92 of the bone plate 12. The lip engaging portion 66 engages the boneplate 12 at one side of the lobe 42 and the notch 84 engages theintermediate portion 20 at the opposite side of the lobe 42. Thisengagement resists lateral movement between the lobe 42 and themanipulator 19 in directions 152, 154 even as the manipulator 19 ispivoted to bend the bone plate 12. Further, this engagement maintains acoaxial alignment of a center line of the lobe through bore 24 and acenter line of the manipulator cannula 110. The aligned center lines ofthe through bore 24 and cannula 110 will be referred to with combinedreference numeral 156. The manipulator 17 is then connected to the lobe40 in a similar manner and establishes a coaxially aligned center line158 of the through bore 22 of the lobe 40 and the cannula 110 of themanipulator 17.

With reference to FIGS. 10 and 11, the manipulators 17, 19 are shownconnected to the lobes 40, 42 of the bone plate 12. At this point, thebone plate 12 is in the initial, unflexed configuration and theintermediate portion 20 of the bone plate 12 has a curved shape. Withthe bone plate 12 in the unflexed configuration, the center lines 156,158 are oriented at an angle 170 that may be the same or substantiallythe same as the angle 53 between the centerlines 50, 52 of the boneplate throughbores 22, 24 with the bone plate 12 in the unflexedconfiguration (see FIG. 2).

Next, the manipulators 17, 19 are pivoted toward each other indirections 130, 132 such as by a user squeezing the manipulators 17, 19together, into an installation orientation as shown in FIG. 12. With themanipulators 17, 19 in the installation orientation, the centerlines156, 158 may be substantially parallel to each other, as shown in FIG.12. Comparing FIGS. 11 and 12, pivoting the manipulators 17, 19 towardeach other flexes the bone plate 12 and bends the intermediate portion20 into a straight configuration. With the bone plate 12 in the flexedconfiguration of FIG. 12, the bone plate 12 is generally planar which isin contrast to the bent configuration of the bone plate 12 shown in FIG.2.

It will be appreciated that the bone plate 12 may have a flexedconfiguration for some procedures where the bone plate 12 is partiallyflexed and the intermediate portion 20 is only partially straightened.Even when the intermediate portion 20 is only partially straightened,the elastic properties of the bone plate 12 will still apply a constant,compressive force against the bones 13, 15 once the bone plate 12 hasbeen secured to the bones 13, 15.

To maintain the manipulators 17, 19 in the installation orientation andkeep the bone plate 12 in the flexed configuration, a restraint 190 maybe connected to proximal end portions 192, 194 of the manipulators 17,19. As shown in FIGS. 14 and 15, the restraint 190 has collars 198, 200and a link portion 210 connecting the collars 198, 200. The restraint190 is connected to the manipulators 17, 19 by advancing the restraint190 in direction 210 so that the collars 198, 200 fit over necks 206,208 of the manipulators 17, 19 and rest against shoulders 212, 214 ofthe manipulators 17, 19. The restraint 190 resists pivoting of themanipulators 17, 19 in directions 220, 222 away from the installationorientation, as shown in FIG. 15. The manipulators 17, 19 and restraint190 may be made materials, such as metals or polymers, sufficientlyrigid to resist the resilient bending of the bone plate 12 back towardits initial, unflexed configuration. For example, the manipulators 17,19 may be made of stainless steel and the restraint 190 may be made fromcarbon fiber polyether ether ketone (PEEK). Further, the manipulators17, 19 and restraint 190 may be disposable or reusable.

With reference to FIG. 16, the collars 198, 200 may fit around theexteriors of the necks 206, 208 of the manipulators 17, 19 which permitsthe cannulas 110 of the manipulators 17, 19 to be unobstructed with therestraint 190 connected to the manipulators 17, 19. The unobstructedcannulas 110 permit access to the through bores 22, 24 of the lobes 40,42 through the cannulas 110.

With reference to FIGS. 17 and 18, the restraint 190 maintains themanipulators 17, 19 and bone plate 12 in an assembled configuration andpermits one-handed handling of the assembly of the bone plate 12,manipulators 17, 19, and restraint 190. This assembly of the restraint190, manipulators 17, 19 and bone plate 12 can be readily maneuvered indirection 230 into position on the bones 13, 15. As shown in FIG. 18,the intermediate portion 20 of the bone plate 12 is in its generallystraight or flat configuration due to the restraint 190 continuing toresist pivoting of the manipulators 17, 19 away from their installationorientation.

As shown in FIG. 18, the manipulators 17, 19 have been used to positionthe bone plate 12 on the bones 13, 15 such that the through bores 22, 24are each positioned over one of the bones 13, 15. Due to the elasticproperties of the bone plate 12, the intermediate portion 20 biases thelobes 40, 42 back toward their unflexed orientations (see FIG. 2). Theengagement of the notches 84 and lip engaging portions 66 of themanipulators 17, 19 resist the lobes 40, 42 returning to the unflexedorientations which causes the intermediate portion 20 to press upwardlyagainst the surface 90 of the manipulators 17, 19 and the lips 58 of thelobes 40, 42 to press downwardly against the lip engaging portion 66 ofthe manipulators 17, 19.

With reference to FIGS. 19 and 20, an instrument, such as a screw driver240, has a shaft 242 with a bone screw 16 connected thereto. The screwdriver 240 and bone screw 16 are advanced in direction 244 into thecannula 110 of manipulator 19 to advance a shank portion 246 of the bonescrew 16 into the through bore 24 of the lobe 42 and drive the shankportion 246 into the bone 15. The screw driver 240 continues to drivethe bone screw 16 into the bone 15 until the head portion 46 of the bonescrew 16 seats within the through bore 24 of the lobe 42, as shown inFIG. 21. This process is repeated to drive the other bone screw 16 intothe through bore 22 of the lobe 40 so that both lobes 40, 42 are securedto the bones 13, 15 as shown in FIG. 22.

Once the bone plate 12 in the flexed configuration has been secured tothe bones 13, 15 the restraint 190 is removed in direction 271 to drawthe collars 198, 200 off of the necks 206, 208 as shown in FIG. 22. Thebone plate engaging members 17, 19 are pivoted in directions 270, 272 tolift the notches 84 of the manipulators 17, 19 off of the intermediateportion 20 of the bone plate 12. Next, the manipulators are shiftedoutwardly in directions 274, 276 in order to unhook the lip engagingportions 66 from below the lips 58 of the lobes 40, 42.

With reference to FIG. 23, the bone plate 12 in the flexed configurationis shown secured to the bones 13, 15. The bone screws 16 have beendriven into the bones 13, 15 to secure the lobes 40, 42 against thebones 13, 15. Due to the elastic properties of the bone plate 12, theintermediate portion 20 returns toward its unflexed configuration 32. Asthe intermediate portion 20 bends upwardly from the bones 13, 15, thebone plate 12 applies tension to the bone screws 16 and compresses thebones 13, 15 together.

In another approach, the bone plate 12 may be made of a shape memorynitinol that shifts in situ from a flexed, installation configuration toan unflexed, compression configuration in response to the temperature ofthe patient. The bone plate 12 may be chilled, such as in a salinesolution, mechanically forced into a straightened configuration, andimplanted in the straightened configuration. As the temperature of thebone plate 12 raises to the internal temperature of the patient, thebone plate 12 will return to its original shape and compress the bones13, 15.

With reference to FIG. 24, a bone compression device 300 is providedhaving a bone plate 302 that flexes within the thickness of the boneplate 302 to apply compression to bones. The bone plate 302 has a body304 with lobes 306, 308 and an intermediate portion 310 connecting thelobes 306, 308. In the unflexed configuration of the bone plate 302, theintermediate portion 310 is curved or bent and extends between planesdefined by upper and lower surfaces 311, 313 of the lobes 306, 308.

To flex the bone plate 302 to a flexed configuration, an instrument 319is provided including manipulators 320, 322 that each have a releasableconnection 324 to the bone plate 302. The releasable connection 324includes a recess 326 of the bone plate 302 and a complimentaryprojection 330 of the associated manipulator 320, 322 configured to forman interlocking, rigid engagement with the recesses 326.

With reference to FIG. 25, the bone plate is shown in the initial,unflexed configuration. With the manipulators 320, 322 connected to thebone plate 302, longitudinal axis 340, 342 of the manipulators 320, 322extend an angle 344 to one another.

Next, handle portions 350, 352 of the manipulators 320, 322 are graspedand pressed toward one another in directions 354, 356 from an initialorientation to an installation orientation. Because the manipulators320, 322 are connected to the lobes 306, 308, pressing the manipulatorhandle portions 350, 352 together deflects the intermediate portion 310from the initial, curved configuration as shown in FIG. 24 to a flexed,straightened configuration as shown in FIG. 26. As the bone plate 302flexes between the unflexed and flexed configurations, the intermediateportion 310 remains between the planes defined by the upper and lowersurfaces 311, 313 of the lobes 306, 308. With the bone plate 302 in theflexed configuration, a user may hold the manipulators 320, 322 in theinstallation orientation and keep the bone plate 302 in the flexedconfiguration with one hand, e.g., between a thumb and an index finger.

With reference to FIGS. 27 and 28, the flexed bone plate 302 has beenpositioned on bones (not shown) and bone screws 360 are advanced indirection 362 into through bores 364 of the lobes 306, 308. Once thebone plate 302 has been secured to bones, the lobes 306, 308 may turnslightly about a bone screw head portion 364 as the intermediate portion310 bends back toward its curved, unflexed configuration and compressesthe bones together via the bone screws 360. To accommodate this slightturning of the lobes 306, 308 about the head portions 364, the headportions 360 may have a non-threaded outer surface 370. If desired,screw retention mechanisms may be provided to resist backout of the bonescrews 360 from the through bores 364 while permitting this turning ofthe lobes 306, 308 about the head portion 364. For example, the lobes306, 308 may each have a lip extending about the through bore 364 thatdeflects out of the way of the bone screw 306 as the bone screw 306 isadvanced into the through bore 364 and then snaps back over the headportion 364 once the head portion 364 is seated within the through bore364.

With reference to FIG. 29, once the bone plate 302 has been secured tothe bones via the bone screws 360, the manipulators 320, 322 may bedisconnected from the bone plate 302. For example, the projections 330may be slid in direction 380 out of the recesses 326. At this point, theflexed intermediate portion 310 biases against the bone screws 360 andcompresses the bone screws 360 and bones connected thereto together asthe intermediate portion returns toward its initial, unflexedconfiguration. As the intermediate portion 310 shifts from itsstraightened toward its curved configuration, the intermediate portion310 travels along the outer surfaces of the bones rather than away fromthe outer surfaces of the bones as does the intermediate portion 20 ofthe bone plate 12 (see FIG. 23).

With reference to FIG. 30, a bone compression device 400 is providedhaving a bone plate 402 that is similar in many respects to the boneplate 302 as discussed above. However, the bone plate 402 has anintegrated installation instrument 403 with manipulators 404, 406 thatmay be used to flex the bone plate 402 and then be removed from the boneplate 402 after installation of the bone plate 402 onto bones. In oneform, the manipulators 404, 406 are integrally formed with a body 408 ofthe bone plate 402. As used herein, the term “integral” is intended torefer to being formed as one piece with another part.

With reference to FIG. 31, the manipulator 404 is connected to the body408 at a frangible portion 410. To deflect the bone plate 402 from aninitial, unflexed configuration to a flexed, installation configuration,a user grasps handle portions 412 of the manipulators 404, 406 andsqueezes the handle portions 412 together generally in direction 414.This pivots the manipulator 404 about the frangible portion 410 indirection 420 and brings a surface 422 of the manipulator 404 intocontact with a surface 424 of the body 408. Stated differently, pivotingthe manipulator 404 in direction 420 closes a gap 426 between thesurfaces 422, 424 with a distance 428 between the surfaces 422, 424,decreasing as the manipulator 404 pivots in direction 420. With thesurfaces 422, 424 abutting, continued squeezing of the handle portions412 together moves the lobes 408 in directions 430 and straightens anintermediate portion 432. Once the bone plate 402 has been installed auser may bend, cut, or otherwise separate the manipulators 404, 406 fromthe bone plate body 408 at the frangible portions 410.

With reference to FIGS. 32, and 33, a bone compression device 500 isprovided having a resilient body 502 connecting bone screws 504, 506.The resilient body 502 includes end portions 508, 510 secured to thebone screws 504, 506 and an intermediate spring portion 512 configuredto apply a compressive force to the bones connected to the bone screws504, 506. The bone screws 504, 506 have blind bores 530 that receive theend portions 508, 510 of the resilient body 502. The bores 530 each havean upper portion with a hex drive configuration to accommodate a hexdriver for driving the bone screws into 504, 506 into bone.

With reference to FIG. 33, a top plan view of the body 502 is providedshowing the body 502 in an unflexed configuration. The body 502 hasstraight portions 516, 518, 520 and curved portions 522, 524 connectingthe straight portions 516, 518, 520. To flex the body 502, the endportions 508, 510 are moved apart from each other in directions 521,523. This causes the elbow portions 522, 524 to elastically flex to amore open configuration as shown in FIG. 34. Further, one or more of thestraight portions 516, 518, 520 may elastically deform in the lengthwisedirection.

To apply compression to bones, the bone screws 504, 506 are driven intothe bones and the end portions 508, 510 of the body 502 are moved apartfrom each other to shift the body 502 to the flexed configurationthereof as shown in FIG. 34. The end portions 508, 510 are held in theirspaced orientation to keep the body 502 flexed and the end portions 508,510 are then advanced into the bores 530 of the bone screws 504, 506previously driven into the bones. The resilient body 502 biases againstthe bone screws 504, 506 in directions 534, 536 as the body 502 returnstoward its unflexed configuration and compresses the bones.

With reference to FIG. 35, the bone compression device 500 includes aretention mechanism 550 for maintaining the end portions 508, 510 in thebores 530 of the bone screws 504, 506. In one approach, the retentionmechanism 550 includes a leading end portion 552 of the resilient bodyend portion 508. The leading end portion 552 has a cam surface 554 andan enlarged portion 556 that snaps past a retention portion 558 of thebone screw 504. More specifically, the retention portion 558 includes anannular collar 564 having an upper surface 560 and a lower surface 562.Advancing the leading end portion 552 in direction 570 into the bore 530engages the cam surface 554 with the upper surface 560 of the collar564. Continued advancing of the leading end portion 552 in direction 570deflects the collar 564 and permits the enlarged portion 556 to snappast the collar 564. With the leading end portion 552 advanced past thecollar 564, an upper surface 574 of the leading end portion 552 isarranged to abut the lower surface 562 of the retention portion 558 andresist back out of the leading end portion 552. In one approach, theleading end portion 508 has a smooth, volcano-shaped neck portion 580spaced from the collar 564 with the leading end portion 552 captured inthe bore 530 by the collar 564. The neck portion 580 permits the endportion 508 to turn within the bore 530 after installation of the bonecompression device 500 which accommodates turning of the straightportion 520 in direction 582 (see FIG. 34) relative to the bone screw504 as the resilient body 502 returns toward its unflexed configuration.The resilient body end portion 508 and bone screw 504 thereby form apivot connection therebetween that permits reconfiguring of theresilient body 502 back toward its unflexed configuration whilemaintaining the end portion 508 securely connected to the bone screw5034.

With reference to FIG. 36, a bone compression device 600 is providedthat is similar in many respects to the bone compression device 500. Thebone compression device 600 includes a resilient body 602 having endportions 604, 606 that are configured to be secured to bone screws 608,610 and a spring portion 612 intermediate the end portions 604, 606. Onedifference between the resilient body 602 and the resilient body 502 isthat the resilient body 602 has straight legs 614, 616 connecting theend portions 604, 606, and the spring portion 612. The straight legs614, 616 reduce turning of the end portions 604, 606 relative to thebone screws 608, 610 as the resilient body 602 returns toward itsunflexed configuration. The straight legs 614, 616 reduce turning of theend portions 604, 606 relative to the bone screws 608, 610 because elbowportions 620, 622 of the spring portion 612 can flex and open as theresilient body 602 shifts toward its flexed configuration while thestraight legs 614, 616 remain generally aligned along an axis 630. Thebone compression device 600 may have retention mechanisms that rigidlyfix the resilient body 602 to the bone screws 608, 610 since the endportions 608, 610 generally do not turn relative to the bone screws 608,610 as the resilient body 602 returns toward its unflexed configuration.

The bone compression devices discussed above may be used in a variety ofapplications, such as hand and foot bone fragment and osteotomy fixationand joint arthrodesis, fixation of proximal tibial metaphysis osteotomy,and adjunctive fixation of small bone fragments. The bone compressiondevices may be used with bones such as the femur, humerus, clavicle,sternum, ribs, and pelvis.

Those skilled in the art will recognize that a wide variety ofmodifications, alterations, and combinations can be made with respect tothe above-described embodiments without departing from the spirit andscope of the invention, and that much modifications, alterations, andcombinations are to be viewed as being within the ambit of the inventiveconcept.

What is claimed is:
 1. A method of preloading a bone compression devicefor subsequent application of the bone compression device to bones, thebone compression device including an elongated resilient member havingan unloaded configuration wherein the elongated resilient member haseither a bent or a straight shape, the elongated resilient memberfurther having a loaded configuration wherein the elongated resilientmember has the other of the bent or the straight shape, the methodcomprising: moving bone anchor receiving portions of the bonecompression device relative to each other from a first configuration ofthe bone anchor receiving portions to a second configuration of the boneanchor receiving portions, the moving of the bone anchor receivingportions causing the elongated resilient member to shift from theunloaded configuration to the loaded configuration; and after moving thebone anchor receiving portions to the second configuration thereof,connecting at least one restraint to a body which is connected to one ofthe bone anchor receiving portions, the body being separate and distinctfrom the at least one restraint and the one bone anchor receivingportion, to inhibit the bone anchor receiving portions from moving fromthe second configuration back toward the first configuration thereofwhich keeps the elongated resilient member from shifting from the loadedconfiguration back toward the unloaded configuration.
 2. The method ofclaim 1, wherein moving the bone anchor receiving portions relative toeach other includes increasing a distance between the bone anchorreceiving portions.
 3. The method of claim 1, further comprisingengaging a tool with one of the bone anchor receiving portions; andmoving the bone anchor receiving portions relative to each otherincludes using the tool to move the one bone anchor receiving portionrelative to the other bone anchor receiving portion.
 4. The method ofclaim 1, further comprising engaging tools with the bone anchorreceiving portions; and moving the bone anchor receiving portionsrelative to each other includes using the tools to move the bone anchorreceiving portions relative to each other.
 5. A method of preloading abone compression device for subsequent application of the bonecompression device to bones, the bone compression device including anelongated resilient member having an unloaded configuration wherein theelongated resilient member has either a bent or a straight shape, theelongated resilient member further having a loaded configuration whereinthe elongated resilient member has the other of the bent or the straightshape, the method comprising: moving bone anchor receiving portions ofthe bone compression device relative to each other from a firstconfiguration of the bone anchor receiving portions to a secondconfiguration of the bone anchor receiving portions, the moving of thebone anchor receiving portions causing the elongated resilient member toshift from the unloaded configuration to the loaded configuration; andafter moving the bone anchor receiving portions to the secondconfiguration thereof, applying at least one restraint to inhibit thebone anchor receiving portions from moving from the second configurationback toward the first configuration thereof which keeps the elongatedresilient member from shifting from the loaded configuration back towardthe unloaded configuration; wherein moving the bone anchor receivingportions relative to each other includes reconfiguring first and secondportions of the elongated resilient member between a first configurationwherein the first and second portions extend transversely to each otherand a second configuration wherein the first and second portions arecoaxial with each other.
 6. A method of preloading a bone compressiondevice for subsequent application of the bone compression device tobones, the bone compression device including an elongated resilientmember having an unloaded configuration wherein the elongated resilientmember has either a bent or a straight shape, the elongated resilientmember further having a loaded configuration wherein the elongatedresilient member has the other of the bent or the straight shape, themethod comprising: moving bone anchor receiving portions of the bonecompression device relative to each other from a first configuration ofthe bone anchor receiving portions to a second configuration of the boneanchor receiving portions, the moving of the bone anchor receivingportions causing the elongated resilient member to shift from theunloaded configuration to the loaded configuration; after moving thebone anchor receiving portions to the second configuration thereof,applying at least one restraint to inhibit the bone anchor receivingportions from moving from the second configuration back toward the firstconfiguration thereof which keeps the elongated resilient member fromshifting from the loaded configuration back toward the unloadedconfiguration; engaging a first tool with one of the bone anchorreceiving portions and engaging a second tool with the other of the boneanchor receiving portions; and moving the bone anchor receiving portionsrelative to each other includes using the tools to move the bone anchorreceiving portions relative to each other.
 7. A method of preloading abone compression device for subsequent application of the bonecompression device to bones, the bone compression device including anelongated resilient member having an unloaded configuration wherein theelongated resilient member has either a bent or a straight shape, theelongated resilient member further having a loaded configuration whereinthe elongated resilient member has the other of the bent or the straightshape, the method comprising: moving bone anchor receiving portions ofthe bone compression device relative to each other from a firstconfiguration of the bone anchor receiving portions to a secondconfiguration of the bone anchor receiving portions, the moving of thebone anchor receiving portions causing the elongated resilient member toshift from the unloaded configuration to the loaded configuration; andafter moving the bone anchor receiving portions to the secondconfiguration thereof, applying at least one restraint to inhibit thebone anchor receiving portions from moving from the second configurationback toward the first configuration thereof which keeps the elongatedresilient member from shifting from the loaded configuration back towardthe unloaded configuration; providing a tool having a distal end portionconfigured to be connected to the bone compression device, the toolhaving a cannula sized to permit a bone screw to be advancedtherethrough and into an opening of one of the bone anchor receivingportions.
 8. A method of applying a bone compression device to bones,the bone compression device including bone anchor receiving portions andan elongated resilient member, the bone anchor receiving portions havinga first configuration which places the elongated resilient member in anunloaded configuration wherein the elongated resilient member has eithera bent or a straight shape, the bone anchor receiving portions having asecond configuration which places the elongated resilient member in aloaded configuration wherein the elongated resilient member has theother of the bent or straight shape, the method comprising: positioningthe bone compression device against the bones with the bone anchorreceiving portions in the second configuration and the elongatedresilient member in the loaded configuration; permitting at least onerestraint to hold the bone anchor receiving portions in the secondconfiguration, the holding of the bone anchor receiving portions in thesecond configuration maintaining the elongated resilient member in theloaded configuration; driving shanks of bone screws through openings ofthe bone anchor receiving portions of the bone compression device andinto engagement with the bones; and disconnecting the at least onerestraint from a body connected to one of the bone anchor receivingportions, the body being separate and distinct from the at least onerestraint and the one bone anchor receiving portion, to permit theelongated resilient member to shift from the loaded configuration towardthe unloaded configuration and urge the bone anchor receiving portionsof the bone compression device from the second configuration back towardthe first configuration.
 9. The method of claim 8, wherein removing theat least one restraint to permit the elongated resilient member to shiftfrom the loaded configuration toward the unloaded configuration includesdecreasing a distance between the bone anchor receiving portions. 10.The method of claim 8, wherein removing the at least one restraint topermit the elongated resilient member to shift from the loadedconfiguration toward the unloaded configuration includes changing anangle between two straight portions of the elongated resilient member.11. The method of claim 8, wherein the bone anchor receiving portionseach have a through opening for receiving a bone screw and a centralaxis of the through opening, the bone compression device including alongitudinal axis intersecting the central axes of the through openingswhen the bone anchor receiving portions are in the first configurationand the second configuration.
 12. The method of claim 8 whereinpermitting the at least one restraint to hold the bone anchor receivingportions in the second configuration includes permitting the at leastone restraint to extend intermediate the bone anchor receiving portionsand removing the at least one restraint includes removing the at leastone restraint from being intermediate the bone anchor receivingportions.
 13. The method of claim 8 further comprising seating heads ofthe bone screws against unthreaded surfaces of the bone anchor receivingportions.
 14. A method of applying a bone compression device to bones,the bone compression device including bone anchor receiving portions andan elongated resilient member, the bone anchor receiving portions havinga first configuration which places the elongated resilient member in anunloaded configuration wherein the elongated resilient member has eithera bent or a straight shape, the bone anchor receiving portions having asecond configuration which places the elongated resilient member in aloaded configuration wherein the elongated resilient member has theother of the bent or straight shape, the method comprising: positioningthe bone compression device against the bones with the bone anchorreceiving portions in the second configuration and the elongatedresilient member in the loaded configuration; permitting at least onerestraint to hold the bone anchor receiving portions in the secondconfiguration, the holding of the bone anchor receiving portions in thesecond configuration maintaining the elongated resilient member in theloaded configuration; driving shanks of bone screws through openings ofthe bone anchor receiving portions of the bone compression device andinto engagement with the bones; and removing the at least one restraintto permit the elongated resilient member to shift from the loadedconfiguration toward the unloaded configuration and urge the bone anchorreceiving portions of the bone compression device from the secondconfiguration back toward the first configuration; wherein drivingshanks of bones screws through openings of the bone anchor receivingportions includes advancing one of the bone screws through a cannula ofa tool connected to the bone compression device.
 15. A method ofapplying a bone compression device to bones, the bone compression deviceincluding bone anchor receiving portions and an elongated resilientmember, the bone anchor receiving portions having a first configurationwhich places the elongated resilient member in an unloaded configurationwherein the elongated resilient member has either a bent or a straightshape, the bone anchor receiving portions having a second configurationwhich places the elongated resilient member in a loaded configurationwherein the elongated resilient member has the other of the bent orstraight shape, wherein at least one restraint holds the bone anchorreceiving portions in the second configuration which maintains theelongated resilient member in the loaded configuration, the methodcomprising: positioning the bone compression device against the boneswith the bone anchor receiving portions in the second configuration andthe elongated resilient member in the loaded configuration; drivingshanks of bone screws through openings of the bone anchor receivingportions of the bone compression device and into engagement with thebones; and removing the at least one restraint to permit the elongatedresilient member to shift from the loaded configuration toward theunloaded configuration and urge the bone anchor receiving portions ofthe bone compression device from the second configuration back towardthe first configuration; wherein the elongated resilient member hasfirst and second portions extending transversely to each other with theelongated resilient member in one of the loaded configuration and theunloaded configuration; and wherein the first and second portions of theelongated resilient member are coaxial with each other with theelongated resilient member in the other of the loaded configuration andthe unloaded configuration.
 16. The method of claim 15, wherein removingthe at least one restraint to permit the elongated resilient member toshift from the loaded configuration toward the unloaded configurationincludes decreasing a distance between the bone anchor receivingportions.
 17. The method of claim 15, wherein removing the at least onerestraint to permit the elongated resilient member to shift from theloaded configuration toward the unloaded configuration includes changingan angle between the first and second portions of the elongatedresilient member.
 18. The method of claim 15, wherein the bone anchorreceiving portions each have a through opening for receiving a bonescrew and a central axis of the through opening, the bone compressiondevice including a longitudinal axis intersecting the central axes ofthe through openings when the bone anchor receiving portions are in thefirst configuration and the second configuration.
 19. The method ofclaim 15 wherein permitting the at least one restraint to hold the boneanchor receiving portions in the second configuration includespermitting the at least one restraint to extend intermediate the boneanchor receiving portions and removing the at least one restraintincludes removing the at least one restraint from being intermediate thebone anchor receiving portions.